This does not surprise me, in fact a Comcast technician told me they do this (on a much smaller scale) by disconnecting or cutting competitors' cable runs to buildings they are working on (and also sometimes their own). I lived in a multi-unit apartment building and one day noticed my internet was down (I was a Comcast subscriber). I was suspicious because a Comcast technician was just out earlier in the day installi…
He never told anyone at Comcast or the other houses. Took hours of battling with phone support and a two day wait to have another tech who came out and identified the problem. He said they do this often to get into houses to find problems but he's supposed to put a note on each door and put a note on our accounts. Whoops.